Profiling of components of rhizoma et radix polygoni cuspidati by high-performance liquid chromatography with ultraviolet diode-array detector and ion trap/time-of-flight mass spectrometric detection

Introduction: Rhizoma et Radix Polygoni Cuspidati (Huzhang in Chinese, HZ) is a traditional medicinal plant in China. Many of the components of HZ have been proved to be bioactive while it is difficult to conduct a comprehensive chemical profiling of HZ as a consequence of the absence of efficient separation system and sensitive detective means. We developed a simple and effective method for comprehensive characterization of constituents in HZ. Objective: To develop a simple and effective method to characterize the components in HZ and provide useful information for subsequent metabolic studies of HZ. Materials and Methods: The components in HZ aqueous extract were characterized by using high performance liquid chromatography with UV diode-array detector (HPLC-DAD) and ion trap/time-of-flight mass spectrometric detection (HPLC-IT/TOF). Stilbenes, anthraquinones, gallates and tannins, naphthalenes and some other compounds were identified and confirmed by diagnostic fragment ions with accurate mass measurements, characteristic fragmentation pathways and relevant published literatures. Results: Among the 238 constituents detected in HZ, a total number of 74 constituents were identified unambiguously or tentatively, including 29 compounds reported for the first time in HZ. Conclusion: The identification and structure elucidation of these chemicals provided essential data for quality control and further in vivo metabolic studies of HZ.Key words: Polygonum cuspidatum, HPLC-DAD, HPLC-IT/TOF, qualitative analysis.